Acute necrotizing ulcerative gingivitis (ANUG) results from an infiltration of the host gingiva by endogenous microflora. The development of ANUG seems to follow conditions that produce a lowered host resistance. For example, ANUG frequently follows an episode of debilitating disease or acute respiratory infection. We have previously noted an increased incidence of ANUG in homosexuals (9.4% incidence and T4/T8=0.5 for homosexuals compared with 0.02-0.08% and T4/T8=2.4 for normals), a group reported to have altered levels of responding lymphocytes (T4/T8=1.1 for health homosexuals). This project will evaluate the systemic immunity of ANUG patients both quantitatively and functionally using peripheral blood samples from patients and health controls to determine whether a reduced state of immune responsiveness exists in these patients. The quantities of granulocytes, monocytes and lymphocytes will be determined using microscopy, flow microfluorometry and monoclonal antibodies. Specifically, granulocytes will be enumerated by staining whole blood smears with Wright-geimsa stain and doing microscopic examinations. Monoclonal antibodies will be used for detection of monocytes, natural killer cells, subsets of T lymphocytes (helpers, suppressors, and immature), B cells and Ia-antigen bearing cells. Lymphocyte blastogenesis will be evaluated by 3H-thymidine uptake following stimulation with concanavalin-A, phytohemagglutinin, pokeweek mitogen, streptokinase-streptodornase, or bacterial lipopolysaccharide. PMNs will be evaluated for peroxide generation, phagocytosis, and locomotion using flow cytometry and digital imaging microscopy. Both quantitative and functional parameters will be evaluated when ANUG is first diagnosed and longitudinally during recovery from ANUG to determine whether the changes in immunity are of short or long term duration and to determine whether changes in either the lymphocytic or granulocytic compartments correlate most closely with the development of ANUG. Preliminary results obtained from a heterosexual man with ANUG showed a decrease in T helper cells and T4/T8 of 1.2, consistent with a slight immunodeficiency. One week later, this patient's T4/T8 was 1.8, having returned to near normal levels. By studying ANUG, we hope to better understand the factors involved in conditions of reduced immunity, and the role of lymphocytes and neutrophils in prevention of and recovery from inflammatory periodontal disease.